The present invention relates to a mounting and balancing device for setting and locking in position knives used in machines for cutting, crushing and chopping food products, particulaly in pork-butchery and for salted products, these machines comprising a number of knives arranged on an axis rotating at high speed in a tank of generally semi-toric shape. The knives are in a spaced-apart relationship at angles of 180.degree., or 120.degree., or 90.degree., or 60.degree., or 30.degree., according to the number of knives, along one single line.
As is known, the rotary speed of the knives in modern-machines, so-called cutter machines, is extremely high since there exists machines rotating normally at 3,000 to 6,000 r.p.m. Such speeds have brought about phenomena which hitherto were negligible but are now the source of serious hazards. Actually, the centrifugal force generated by the rotation of the knives reaches very high values tending to displace them relative to the shaft on which they are mounted and, in spite of the precautionary measures taken, some of the knives are displaced, with all the disastrous consequences involved that can be imagined since said knives come in contact with the machine tank, break, deeply score said tank and are in danger to be transformed into projectiles extremely dangerous for the surrounding personnel. On the other hand, the metallic splinters make the products being treated unusable and the price of such unusable products is high since several hundreds of kilogrammes are often treated in one single working pass.
One should also note that the very high rotation speed generates vibrations if the knives are not carefully balanced. Actually, the weights of new knives are little different, but substantial deviations inevitably appear after a few sharpenings, which can reach differences of a several tens of grammes. Vibrations which are thus caused bring about a general fatigue of the machine, the deterioration of the bearings of the knife holding shaft and a deafening noise in the work-shop with as consequence painful conditions for the operators.
Attempts have already been made to remedy such disadvantages with various mechanical solutions regarding the suppression of the displacement of the knives under the effect of the centrifugal force as well as the vibrations due to the lack of balance by using complementary re-balancing devices. However, the existing devices exhibit usually, together or separately, various disadvantages or limitations to their use, such as a high price, reduced setting possibilities, limited balancing possibilities, restrictions as to the choice of the number of knives used and the way to arrange them on the knife holding shaft, etc.
The present invention remedies such drawbacks by providing a balancing and clamping device ensuring complete safety.